Rating: 
Hill’s Prescription Diet W/D Canine dry dog food gets the Advisor’s lowest rating of 1 star.
The Hill’s Prescription Diet W/D Canine product line lists 2 dry dog foods, each designed to provide “weight control, diabetic, and digestive support for dogs prone to excess weight gain”1.
Since we could not locate AAFCO nutritional adequacy statements for these products on the Hill’s website, we’re unable to report life stage recommendations.
- Hill’s Prescription Diet W/D Low Fat Diabetic GI
- Hill’s Prescription Diet W/D Low Fat Diabetic GI with Chicken
Hill’s Prescription Diet W/D Canine dry dog food was selected to represent both products for this review.
Hill's Prescription Diet W/D Canine Low Fat Diabetic GI
Dry Dog Food
Estimated Dry Matter Nutrient Content
Ingredients: Whole grain corn, powdered cellulose, chicken by-product meal, corn gluten meal, chicken liver flavor, soybean mill run, soybean oil, dried beet pulp, soybean meal, caramel color, potassium chloride, calcium sulfate, flaxseed, l-lysine, vitamin E supplement, choline chloride, vitamins (l-ascorbyl-2-polyphosphate (source of vitamin C), vitamin E supplement, niacin, thiamine mononitrate, vitamin A supplement, calcium pantothenate, biotin, vitamin B12 supplement, pyridoxine hydrochloride, riboflavin, folic acid, vitamin D3 supplement), calcium carbonate, taurine, minerals (ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate, sodium selenite), iodized salt, l-tryptophan, l-carnitine, l-threonine, preserved with mixed tocopherols & citric acid, phosphoric acid, beta-carotene, rosemary extract
Fiber (estimated dry matter content) = 16.4%
Red items when present indicate controversial ingredients
The first ingredient in this dog food is corn. Corn is an inexpensive and controversial cereal grain of only modest nutritional value to a dog.
For this reason, we do not consider corn a preferred component in any dog food.
The second item is powdered cellulose, a non-digestible plant fiber usually made from the by-products of vegetable processing. Cellulose is sometimes added to dilute the number of calories per serving and to give the feeling of fullness when it is eaten.
Except for the usual benefits of fiber, powdered cellulose provides no nutritional value to a dog.
The third ingredient is chicken by-product meal, a dry rendered product of slaughterhouse waste. It’s made from what’s left of a slaughtered chicken after all the prime cuts have been removed.
In a nutshell, chicken by-products are those unsavory leftovers usually considered “unfit for human consumption”.
In addition to organs (the nourishing part), this stuff can contain almost anything — feet, beaks, undeveloped eggs — anything except quality skeletal muscle (real meat).
On the brighter side, by-product meals are meat concentrates and contain nearly 300% more protein than fresh chicken.
After the chicken liver flavor, we find soybean mill run.
Mill run is a by-product, mostly the hulls of soybeans remaining after processing the beans into meal. This is nothing more than a cheap, low-quality filler more commonly found in cattle feeds.
The sixth ingredient is corn gluten meal. Gluten is the rubbery residue remaining once corn has had most of its starchy carbohydrate washed out of it.
Compared to meat, glutens are inferior grain-based proteins lower in many of the essential amino acids dogs need for life.
This inexpensive plant-based ingredient can significantly boost the total protein content reported in this dog food.
The seventh ingredient is soil oil, red flagged here only due to its rumored (yet unlikely) link to canine food allergies.
However, since soybean oil is high in omega-6 fatty acids and contains no omega-3′s, it’s considered less nutritious than canola or flaxseed oils.
The eighth ingredient is beet pulp. Beet pulp is a controversial ingredient, a high fiber by-product of sugar beet processing.
Some denounce beet pulp as an inexpensive filler while others cite its outstanding intestinal health and blood sugar benefits.
We only call your attention here to the controversy and believe the inclusion of beet pulp in reasonable amounts in most dog foods is entirely acceptable.
The ninth ingredient is soybean meal. Soybean meal is actually a useful by-product. It’s what remains of soybeans after all the oil has been removed.
Soybean meal contains 48% protein. However, compared to meat, this item is considered an inferior plant-based protein providing a lower biological value.
From here, the list goes on to include a number of other items.
But to be realistic, ingredients located this far down the list (other than nutritional supplements) are not likely to affect the overall rating of this product.
With two notable exceptions…
First, we find no evidence of probiotics, friendly bacteria applied to the surface of the kibble after processing.
And lastly, the minerals listed here do not appear to be chelated. And that can make them more difficult to absorb. Non-chelated minerals are usually associated with lower quality dog foods.
Hill’s Prescription Diet W/D Canine Dry Dog Food
The Bottom Line
Even though this is a prescription product, we continue to limit our judgment to the estimated meat content of the recipe as well as the apparent quality of its ingredients. And nothing else.
Our ratings have nothing to do with the accuracy of claims made by the manufacturer as to this product’s ability to effectively treat or cure a specific health condition.
So, to find out whether or not this dog food is appropriate for your particular pet, you must consult your veterinarian.
With that understanding…
Judging by its ingredients alone, Hill’s Prescription Diet W/D Canine looks to be a below-average dry dog food.
But ingredient quality by itself cannot tell the whole story. We still need to estimate the product’s meat content before determining a final rating.
The dashboard displays a dry matter protein reading of 19%, a fat level of 9% and an estimated carbohydrate content of 64%.
Both W/D dry foods exhibit the same nutrient percentages.
Low protein. Low fat. And high carbohydrates when compared to a typical dry dog food.
However, when you consider the protein-boosting effect of the corn gluten and soybean meals, this looks like the profile of a dry dog food containing only a limited amount of meat.
What good W/D does by saving fat, it loses in protein and gains in carbohydrates. Plus it’s difficult to ignore the presence of so many undesirable red flag items.
Bottom line?
Hill’s Prescription Diet W/D is a plant-based dry dog food using only a limited amount of chicken by-product meal as its main source of animal protein, thus earning the brand 1 star.
Not recommended.
Those looking for a slightly better weight loss kibble from the same company may wish to visit our review of Hill’s Prescription Diet R/D dry dog food.
A Final Word
This review is designed to help you make a more informed decision when buying dog food. However, our rating system is not intended to suggest feeding a particular product will result in specific health benefits for your pet.
For a better understanding of how we analyzed this product, please be sure to read our article, “The Problem with Dog Food Reviews”
Remember, no dog food can possibly be appropriate for every life stage, lifestyle or health condition. So, choose wisely. And when in doubt consult a veterinarian for help.
Have an opinion about this dog food… or maybe the review itself? Please know… we welcome your comments.
Notes and Updates
01/03/2010 Original review
08/08/2010 Review updated
11/13/2011 Review updated, name change only
- Hill’s Pet Nutrition Website, 8/8/2010 ↩
The Dog Food Advisor publishes independent reviews to help pet owners make better choices when shopping for dog food.
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